Diabetes mellitus is a metabolic disease primarily characterized by a chronic hyperglycemic state due to impaired insulin action. The treatment of diabetes is generally performed by drug therapy together with diet and exercise therapy. Examples of oral anti-diabetic agents include biguanides and thiazolidinediones that improve insulin resistance; sulfonylureas and glinides that promote insulin secretion from pancreatic β cells; and α-glucosidase inhibitors that inhibit sugar absorption.
However, it is reported that they have side effects: biguanides produce gastrointestinal symptoms and lactic acidosis; thiazolidinediones produce weight gain and edema; sulfonylureas and glinides produce hypoglycemia or secondary failure due to long-term use; and α-glucosidase inhibitors produce diarrhea etc. Therefore, development of an oral hypoglycemic agent which can address such problems is desired.
In recent years, piperidine compounds have been developed as oral anti-diabetic agents having new structures. (see, for example, Patent Literature 1 to 4).